Question

I’d like to have a MATLAB array fill a column with numbers in increments of 0.001. I am working with arrays of around 200,000,000 rows and so would like to use the most efficient method possible. I had considered using the following code:

for i = 1 : size(array,1)
    array(i,1) = i * 0.001;
end

There must be a more efficient way of doing this..?

Answer 1

array(:,1) = [1:size(array,1)]' * 0.001;

Matlab is more efficient when vectorizing loops, see also the performance tips from mathworks.

If such vectorization is infeasible due to space limitations, you might want to reconsider rewriting your for-loop in C, using a MEX function.